As is well known, shock absorbers of the type commonly used in automotive vehicles, aircraft and the like include a hydraulic cylinder and piston operating within a reservoir and a valve for controlling the flow of hydraulic fluid between the cylinder and the reservoir. In addition, a sealed gas filled cushion has been installed in the reservoir to occupy the space not filled by the liquid so as to minimize any possibility of gas or air mixing with the hydraulic liquid and interfering with the proper operation of the shock absorber, also to match the metal volume of the extending or piston rod in extension. Problems have been encountered in the production of such heretofore suggested gas-cushion shock absorbers because the gas filled bags are difficult to handle and assemble into the limited space within the reservoir and around the cylinder.